The Russian ruble has gained back some of the value it lost in a steep slide that brought the currency's exchange rate to as low as 80 to the U.S. dollar this week.

It took less than 62 rubles to buy a dollar in Moscow late on December 17, but trading remained volatile.

The recovery from the record lows it hit the previous day -- dubbed "Black Tuesday" by some in Russia -- came after the Finance Ministry said it was moving to support the ruble by selling foreign currency.

It also comes a day before a December 18 press conference by Russian President Vladimir Putin that is expected to address the country's economic woes.

Putin's spokesman says the Russian president would not make a statement about the ruble crisis before that press conference.

Dmitry Peskov told Russian television "It is quite reasonable to presume that in a matter of days a whole range of measures will be put forward in order to minimize the consequences of the crisis -- or possible negative consequences of crisis elements -- for the country's population."

Russian Finance Ministry spokeswoman Svetlana Nikitina said on December 17 that the ministry "considers the ruble extremely undervalued and is starting to sell its leftover currency on the market."

It was not immediately clear how much of Russia's foreign currency reserves have been sold in recent days in order to support the ruble.

The ruble has lost more than half its value against the dollar since the start of the year, largely due to a slump in global oil prices and Western sanctions against Russia over its interference in Ukraine.

Russia's central bank has spent more than $10 billion from its currency reserves during December and raised its key interest rate twice since December 11 by a total of 7.5 percentage points, to 17 percent.

The biggest rise -- and the sixth during 2014 -- came on December 15 when the central bank raised the interest rate by 6.5 percentage points.

Russia's interest rate has more than tripled since March, when Russia annexed Crimea from Ukraine. Back then, the interest rate had been set at 5.5 percent.

These moves set off a rush by consumers in Russia to spend their rubles amid fears of further declines and warnings from economists that Russia was suffering not just from a financial crisis, but a full-fledged economic crisis.

On December 16, technology giant Apple announced it was halting online sales of its iPhones, iPads, and other products in Russia because the ruble's value is too volatile for it to set prices.

The company last month increased its prices in Russia by 20 percent after the weakening ruble left products in the country cheaper than in the rest of Europe.